Decision making statements are used in the Python programs to make them able to decide which of the alternative group of instructions to be executed, depending on value of a certain Boolean expression.

Python provides if..elif..else control statements as a part of decision marking.

marks = 80 
result = ""
if marks < 30:
   result = "Failed"
elif marks > 75:
   result = "Passed with distinction"
else:
   result = "Passed"

print(result)

Most of the processes require a group of instructions to be repeatedly executed. In programming terminology, it is called a loop. Instead of the next step, if the flow is redirected towards any earlier step, it constitutes a loop.

If the control goes back unconditionally, it forms an infinite loop which is not desired as the rest of the code would never get executed.

• For loop

words = ["one", "two", "three"]
for x in words:
  print(x)

• While loop

i = 1
while i < 6:
  print(i)
  i += 1